Due to the factor of cost and character of the passive components, the passive components can not be integrated inside the Integrated circuits completely, but need to Implemented by outside connecting methods, etc. . . . These methods will easily cause the shortcoming of low reliability, high manufacturing cost and such that the area of the substrate can not easily be reduced. Thus, the co-fired technology is provided to solve the above mentioned problem. The co-fired technology mainly uses oxide materials in the manufacturing environment with high temperature and oxygen to make the oxide electrodes instead of the metal electrodes on the oxide ceramic layer manufactured from Insulating ceramic materials to form the multi-layer or single-layer oxide ceramic components.
The co-fired technology can easily achieve the integration ability of the module and the passive components, and the considerations of space and cost can be better taken into account. By stacking the ceramic substrates with several micro meter thicknesses and embedding the ceramic substrates into the passive components and integrated circuits, the passive components and the circuit wiring can be centralized inside the substrate more efficiently to achieve to purpose of saving space and reducing cost. The co-fired technology has become the development trend of future integrated and modular electric components via the excellent electrical, mechanical and thermal character.
The resistor manufacturing method using the prior co-fired technology includes the following steps. First, an aluminum oxide substrate is made by insulation materials. Then, a resistive layer is disposed on the surface of the aluminum oxide substrate by printing or sputter conductive materials. Then, a protective layer is disposed on the resistive layer by using insulating ceramic materials such that the protective layer is as the substrate for another resistive layer. The above steps are repeated to stack multiple layers of resistive layers. Finally, the whole resistor is package by disposing an insulating protective layer, and then sintered and shaped. In addition, a pair of terminal poles is electrically connected to two terminal planes of each resistive layer to form a completed resistor.
However, the above mentioned resistor manufacturing method is arranged for the general single-layer resistor. The resistor with stack structure is manufactured just by repeating the same method for extend the function. The process is complex and trivial, and the co-fired technology is not utilized for the most efficient use.